MAX97236EVKIT+ Maxim Integrated Products, MAX97236EVKIT+ Datasheet - Page 11

• Manufacturer Part Number: MAX97236EVKIT+
• Description: Audio Modules & Development Tools MAX97236 Eval Kit
• Manufacturer: Maxim Integrated Products

Specifications of MAX97236EVKIT+

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The headphone amplifier is optimized for low-power
consumption and low noise. A charge pump generates
a negative and positive supply voltage that powers the
headphone amplifier and eliminates the need for a large
output coupling capacitor.
The headphone amplifier has volume control from -60dB
to +6dB. A single-pole filter, f
signals outside the audio band.
The charge pump powers the headphone amplifier.
When a headphone load is connected and the audio
output signal is small, the charge pump outputs a Q0.9V
negative and positive supply voltage. When a large
audio signal is applied, the output rails of the charge
pump switch to a higher voltage mode, Q1.8V. The
higher voltage rails accommodate the higher voltage
swing necessary to amplify line level audio signals. The
lower voltage rails reduce the power consumption of the
headphone amplifier when higher rails are not needed.
The Class H amplifier employs a class AB output stage
with power-supply voltages that shift based on the output
signal needs
Class H DirectDrive Headphone Amplifier
D3, E2
BUMP
C4
C5
D1
D2
D4
D5
E1
E3
E4
E5
(Figure
MICVDD
SLEEVE
MOUTP
RING1
MBIAS
RING2
NAME
PGND
C1N
SDA
C1P
V
with Dual-Mode Charge Pump
DD
1). The lower power supply rails are
Detailed Description
Positive Microphone Output
Jack Input 2/Right Headphone Output. Connect to the first ring of the four-pole jack.
Charge-Pump Flying Capacitor Negative Connection. Connect 1FF between C1N and C1P.
Serial-Data I/O
Power Ground. Ground Return for the charge pump.
Microphone Bias Capacitor Connection. Connect 1FF to GND.
Microphone Power-Supply Input. Bypass to GND with 1FF.
Charge-Pump Flying Capacitor Positive Connection. Connect 1FF between C1N and C1P.
Main Power-Supply Input. Connect to 1.8V and bypass to GND with 1FF.
Microphone Input Headset GND. Connect to the second ring of the four-pole jack.
Microphone Input Headset GND. Connect to the sleeve of the four-pole jack.
Audio Amplifier with Jack Detection
Dual-Mode Charge Pump
-3dB
= 85kHz, attenuates
Class H Operation
used when the output voltage requirements are below
the 0.5V threshold. The higher supply rails are used
when the output voltage is above the 0.5V threshold,
maximizing output power and voltage swing. The switch
between available power-supply voltages occurs on a
cycle-by-cycle basis.
Figure 1. Class H Power-Supply Operation
V
V
-0.9V
-1.8V
TH_H
1.8V
0.9V
TH_L
FUNCTION
Pin Description (continued)
OUTPUT VOLTAGE
PVDD
PVSS
32ms
32ms
THRESHOLD
11